Adjustable muffler



May 4, 1965 E. w. B01-TUM 3,181,648

ADJUSTABLE MUFFLER Filed 001'.. l, 1962 3,181,648 ADJUSTABLE MUFFLER Edward W. Bottom, 9357 Spencer, Brighton, Mich. Filed Oct. 1, 1962, Ser. No. 227,439 3 Claims. (Cl. 181-63) The present invention relates to an adjustable muffler, and more particularly to a muffler for use in reducing pulsations and noise in systems in which air or other gas flows, the muffler being adjustable to be effective in different systems.

The muffler of the present invention may be used in any system in which a gas must be exhausted, such as from the operation of a gasoline or other engine or in connection with the compressor of a refrigeration system. The muffler may be used on either the suction or discharge side of a compressor or engine. However, the greatest effect from the muffler is normally achieved by installing it in the discharge line of a compressor or the exhaust line of an engine. The muffler is particularly i useful in refrigeration systems where the elimination of noise is highly important.

The use of muillers has, of course, been quite common in the past. However, the use of conventional prior art mufflers has to some extent been unsatisfactory in systems where high quality muffler performance is necessary. The configuration of the muffler is very important Vwith reference to the performance of the muffler. The

pressure drop and orifice conditions in the muffler can significantly effect muffler performance. Muffler performance is particularly important in refrigeration systems where the pressure drop through the muffler and the amount of noise suppression in the muffler are very important. A muffler may perform satisfactorily with one refrigeration compressor at a given suction pressure or load condition. However, if the operating conditions of the compressor are changed, or if the muffler is utilized in a different system, resulting in a different pressure drop through the muffler, the performance of the muffler may be quite unsatisfactory.

The present muffler construction is particularly adapted for use in systems of large capacity. In my copending application Serial No. 222,411, filed September 10, 1962, now U.S. Patent No. 3,141,519, I have described an adjustable mufller which is particularly suitable for systems of relatively small capacity. However, it is to be appreciated that the `different muffler designs may be utilized in connection with any systems to which they may be adapted, whether the system be of large capacity or small capacity.

It is an object of the present invention to provide an adjustable mufller.

A further object of the present invention is to provide an adjustable muffler which is particularly suitable for use in a system of relatively large capacity.

Another object of the invention is to provide a muffler which, when installed in a system, may be adjusted to vary the orifice openings within the mufller with a consequent variation to the resistance of flow in the muffler.

A further object of the invention is to provide a muffler having a plurality of baffles with orifice openings which are adjustable externally of the mufller without the escape of gas from the system.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE l is a view in perspective of one embodiment of an adjustable muffler according to the present inven- United States Patent O tion with portions of the casing broken away for the purpose of clarity;

FIGURE 2 is a sectional View of the adjustable muffler of FIGURE 1 taken substantially along the line 2-2 looking in the direction of the arrows; and

FIGURE 3 is a view in section of another embodiment of the invention.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to FIGURE l, it will be seen that the mufiler 1) comprises a casing including a hollow cylindrical member 12 having end closures 14, 16 secured thereto. The closures 14, 16 may be secured to the member 12, as may be other components of the muffler, by any suitable method such as brazing.

An inlet fitting 18 is provided on the end closure 14 and and outlet fitting 20 is provided on the end closure 16. The inlet and outlet are suitably attached to conduits (not shown) in the system in which the muffler is used.

Secured within the cylindrical member 12 are a plurality of spaced apart cup-shaped baffle plates 22. Each baffle plate 22 is provided with a small opening 24 adjacent the lower portion of member 12 for the flow of oil through the mufller. Oil is, of course, present in the gases of a refrigeration system.

A relatively large opening 26 is provided centrally of each plate 22. The openings 26 are provided for the flow of gas through the muffler.

A disc-shaped closure member 28 is provided for each opening 26. The closure members 28 are provided to permit variation of the orifices formed by the openings 26 of the baffles 22.

Dlametrically opposed shaft sections 30, 32 are provided on each closure member 28. The shaft sections are journaled in bearing brackets 34, 36 which are secured to the baffles 22. The shaft section 30 is elongated and extends through an opening in the cylindrical member 12 to terminate exteriorly of the casing. A support and sealing member 38 is provided for the shaft section 30. The member 38 is received in an opening 40 of the casp ing member 12 and is secured thereto. The member 38 has an axial opening 42 through which the shaft section 30 extends. As will be noted, the shaft section 30 has a wrench engageable head 44 for rotating the shaft with consequent rotation of the closure 28 to vary the position thereof with respect to the opening 26 in the baffle.

A packing gland 46 is provided to seal the opening 42 against escape of gas from within the mufller. The gland 46 is conventional in structure, comprising a nut 48 which is threadingly received in internally threaded recess 50 of the member 38. An annular sealing element 52, fabricated from asbestos-graphite or the like, is positioned within the recess 50 and is wedged into sealing engagement with the shaft section 30 and angular wall portion 54 by the nut 48.

The shaft section 30 is externally threaded at 56 adjacent to the outer surface of the nut 48. A nut 58 is received on the shaft section 30 and, when tightened against the nut 48, acts to lock the shaft 30 against rotation.

An internally threaded cap 60 is received on external threads 62 of the member 38. The cap 60 serves to further seal the muffler so that any gas which does escape by the sealing element S2 is further restricted from escaping from the system. The cap 60 is, of course, removed when it is desired to adjust the shaft section 3Q.

In operation of the muffler 10, the muffler is installed in aisystem by attachment of suitable conduits to the inlet and outlet 18, Ztl. The cap 60 is then removed, the nut 58 is threaded out of engagement with the nut d8, and .the shaft section 30 is rotated to pivot the closure element 2S to different angular positions with respect to the bafe 22. This adjustment varies the size of the orifice through the baffle 22. The extent of adjustment, which is made While the system is in operation', is determined bythe noise level of the muffler. That is, the shaft 30 is adjusted axially to achieve the lowest possible noise level. When the adjustment has been made, the nut 58 is tightened and the cap 60 is replaced.

Variations in the size of the orifice openings varies the resistance to the flow of gas.' This is of importance in muler performance. Additionally, changing the position of the closures will Vary the deflection of the gas and change lthe turbulence characteristics of thev gas which are also important factors in muffler performance.

An alternate construction is illustrated in FIGURE 3. As will be noted, a plurality of baffles are provided Within the muffler casing 66. The FIGURE 3 construction differs from that of FIGURE l in that the bafiie plates 64 are pivotally mounted within the muiiler casing 66. Each baffle ne is pivotally mounted at 68 and has a shaft 7f3 diametrically opposite therefrom which extends through a support and sealing structure 72. The Struc- Yture 72 is the same as that described in connection with the member 38 and associated components and conse- Vquently the description thereof is not repeated at this point.

The operation of the FIGURE 3 embodiment is sub stantially the same as embodiment. The shaft 'iti is rotated until optimum mufiler performance is achieved. The orifice through the muffler is formed by the outer periphery of the baffle 64 and the inner surface of the casing 66.

The muffler structure illustrated in the various figures may be modified as desired to suit particular conditions. For example, only the orices of the first or second baffle plates nearest the outlet or inlet may be made adjustable. Additionally, with reference to the FIGURE 1 showing, the closures on the shaft may be in any shape or configuration to provide the desired muffler characteristics.

Once the muffler of the present invention is installed, it may be quickly adjusted to the system to provide best performance. This eliminates the time and expense involved in installing different muliiers to achieve top performance. Additionally, an adjustable Vrnufer provides an almost infinite range of adjustment which is not possible by merely varying the size of the muffler which is installed.

Having thus described my invention, I claim:

1. An adjustable muffler comprising a casing having an inlet andan outlet, at least one baie in the casing, said baffle having an opening therein for the passage of in the case of the FIGURE l tive to pivot the closure member to different adjusted posi- Y tions from fully closed to fully open to thereby adjust the size of said orifice, means to lock the closure member in any adjusted position from fully open to fully closed,

sealing means between theshaft and casing forming a i gas-tight seal, and a cap over the external portion of the shaft to effect an additional gas-tight seal.

2. An adjustable mufller comprising a casing having an inlet and an outlet, at least one baffle in the casing, 'said baiiie being pivotally mounted on the casing interior, said baliie being pivotal to positions to form an orifice with the casing interior surface for the passage of gas by the baffle, said casing having an opening in the side wall thereof, a shaft 'extending from `the exterior of the casing through said opening into said casing, said shaft being operably connected to the bafe to permit external pivoting of the baffle `to different adjusted positions from fully closed to fully open to thereby adjust the size of said orifice, means to lock the closure member in any adjusted position from fully open to fully closed, sealing means between the shaft and casing forming a gas-tight seal, and a cap over the external portion of the shaft to effect an additional gas-tight seal.

3. An adjustable muffler comprising a casing having an inlet and an outlet, said casing having an opening therein for the passage of gas therethrough, a pivotallyY mounted closure member associated with said Vopening to form an adjustable orifice, said casing having an opening in the side wall thereof, a shaft extending through said opening into the casing from the exterior thereof, said shaft being operably connected Vto the closure member, rotation of said shaft being effective to pivot the closure member to different adjusted positions from fully closed to fullyv open to thereby adjust the size of said orifice, means to lock the closure member in any adjusted position from fully open to fully closed, sealing means between the shaft and casing forming a gas-tight seal, and a cap over the externalportion ofthe shaft to effect an additional gas-tight seal.

References Cited in the le of this patent UNITED STATES PATENTS 

1. AN ADJUSTABLE MUFFLER COMPRISING A CASING HAVING AN INLET AND AN OUTLET, AT LEAST ONE BAFFLE IN THE CASING, SAID BAFFLE HAVING AN OPENING THEREIN FOR THE PASSAGE OF GAS THEREBY A PIVOTALLY MOUNTED CLOSURE MEMBER ASSOCIATED WITH SAID OPENING TO FORM AN ADJUSTABLE ORIFICE, SAID CASING HAVING AN OPENING IN THE SIDE WALL THEREOF, A SHAFT EXTENDING THEREOF, SUCH SHAFT BEING OPERABLY CONNECTED THE EXTERIOR THEREOF, SUCH SHAFT BEING OPERABLY CONNECTE TO THE CLOSURE MEMBER, ROTATION OF SAID SHAFT BEING EFFECTIVE TO PIVOT THE CLOSURE MEMBER TO DIFFERENT ADJUSTED POSITIONS FROM FULLY CLOSED TO FULLY OPEN TO THEREBY ADJUST THE SIZE OF SAID ORIFICE, MEANS TO LOCK THE CLOSURE MEMBER IN ANY ADJUSTED POSITION FROM FULLY OPEN TO FULLY CLOSED, SEALING MEANS BETWEEN THE SHAFT AND CASING FORMING A GAS-TIGHT SEAL, AND A CAP OVER THE EXTERNAL PORTION OF THE SHAFT TO EFFECT AN ADDITIONAL GAS-TIGHT SEAL. 